It is our objective to uncover similarities in the synthesis, structure and function of herpesvirus proteins that will expedite development of diagnostic and therapeutic approaches to herpesvirus related diseases. Our focus to date has been on the structural proteins of herpes simplex, types 1 (HSV-1) and 2 (HSV-2), and of cytomegalovirus (CMV). Results of pilot studies have demonstrated close similarities between counterpart proteins of each virus. The studies proposed here will be directed primarily at CMV and will focus on specific proteins that pilot studies suggest play central roles in the life cycle of this virus, namely; (1) external envelope proteins of the infectious virion, since they are likely to be involved in eliciting the host immune response, (2) an external nucleocapsid protein that appears to function in DNA-packaging and nucleocapsid envelopment, (3) and "immediate early" cytoplasmic protein that may be a direct analogue of the HSV immediate early protein, and (4) an "early" nuclear protein that is made in large amounts and binds DNA. Our experimental methods will be based on existing techniques of cell and particle fractionation, column sizing and affinity chromatography, one- and two-dimensional gel electrophoresis, peptide comparisons and immunological identification. It is anticipated that results of these studies will help to determine whether there are type-specific differences between isolates of HCMV, and whether HCMV shares any group-common antigens with HSV. In addition, studies of the "early" and "immediate early" gene functions are expected to lead to a better understanding of early events in the herpesvirus life cycle that may be important to modulating the latent state of these viruses.